Niggurath The Gibbering Plauge

You may pay 5 life to cast this spell.
Niggurath enters the battlefield under its owner's control.
{2}{b}{u}{u}: Put Niggurath into target players
hand.
At the beginning of your upkeep if you are not
the owner of Niggurath, you lose amount of
life equal to the number of cards in your hand.
(This ability activates while in the hand.)